1. Field of the Invention
This invention relates to flexible ballistic composites that have improved resistance to pick up of water and other liquids, a method for their manufacture and articles, such as body armor, made therefrom.
2. Description of the Related Art
Ballistic resistant products for vests and the like are known in the art. Many of these products are based on high tenacity fibers, such as extended chain polyethylene fibers and aramid fibers. Body armor, such as bullet-resistant vests, may be formed from rigid composites and/or flexible composites.
Rigid body armor provides good ballistic resistance, but is also very stiff and relatively bulky. As a result, in general, rigid body armor garments (e.g., vests) are usually less comfortable to wear than flexible body armor garments. Rigid body armor is also referred to as “hard” armor, which has been defined in the art (see, for example, U.S. Pat. No. 5,690,526) to mean an article, such as a helmet or panels for military vehicles, which has sufficient mechanical strength so that it maintains structural rigidity when subjected to a significant amount of stress and is capable of being free-standing without collapsing. In contrast to such rigid or hard armor, is flexible of “soft” armor which does not have the attributes associated with the hard armor previously mentioned. Although flexible body armor based on high tenacity fibers has excellent service experience, its resistance to pick-up of water and other liquids may be less than desired, depending on the type of fibers present. That is, such armor tends to pick up more water (or other liquid) than desired after being brought in contact with or submersed in water (or the other liquid).
U.S. Pat. No. 5,690,526 and PCT publication WO0029468 are directed to rigid body armor and components thereof which incorporate a polyurethane resin, but there is no disclosure of improved resistance to pick-up of water and other liquids.
It would be desirable to provide a flexible ballistic composite material which has improved resistance to pick-up of water and other liquids, while retaining its desirable ballistic and other properties. It would also be desirable to provide a armor, such as body armor, based on such a material which likewise has improved resistance to pick-up of water and other liquids. Such armor desirably would be comfortable to wear and not costly to manufacture.